Paraoxonase (PON1) is one of the antioxidant enzymes that protects lipoproteins against oxidative conditions. The aim of this study was to investigate the protective effects of Terfezia boudieri on the changes caused by CCl4 in HDL, total antioxidant levels and arylesterase (ARE) activities. Thirty wistar rats were divided into five groups, each including six rats. Group 1 was assigned as the control group and CCl4 was not administered to this group. The rats in the other groups (CCl4, TBE500, TBE1000 and TBE1500) were injected intraperitoneally with CCl4 (1.5ml/kg, 1:1 in olive oile) on 14th day. Rats in the TBE500, TBE1000 and TBE1500 groups were gavaged each day with 500, 1000, and 1500mg/kg aqueous solutions of TPE, respectively for fourteen constitutive days before CCl4 intoxication. After the experimental procedures, blood samples were taken from each animal. The effects of TBE and CCl4 were evaluated by ARE, HDL and total antioxidant measurements in serum samples. Administration of CCl4 reduced the total antioxidant (TAC), HDL levels and ARE activities in the serum. However, in the rats given a pretreatment with TBE 14 days before the injection of CCl4, the reduction caused by the CCl4 in the total antioxidant, HDL levels and ARE activities was prevented at a significant level(p<0.05). We conclude that TBE might have antioxidative effects and may slow the progression of atherogenesis by reducing oxidation of lipoproteins and preserving arylesterase activity.